//: C22:MultipleInheritance4.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// "Tying off" virtual bases
// so you don't have to worry about them
// in derived classes
#include "../purge.h"
#include <iostream>
#include <vector>
using namespace std;

class MBase
{
public:
// Default constructor removes responsibility:
    MBase(int = 0) {}
    virtual char* vf() const = 0;
    virtual ~MBase() {}
};

class D1 : virtual public MBase
{
public:
    D1() : MBase(1) {}
    char* vf() const {
        return "D1";
    }
};

class D2 : virtual public MBase
{
public:
    D2() : MBase(2) {}
    char* vf() const {
        return "D2";
    }
};

class MI : public D1, public D2
{
public:
    MI() {} // Calls default constructor for MBase
    char* vf() const {
        return D1::vf(); // MUST disambiguate
    }
};

class X : public MI
{
public:
    X() {} // Calls default constructor for MBase
};

int main()
{
    vector<MBase*> b;
    b.push_back(new D1);
    b.push_back(new D2);
    b.push_back(new MI); // OK
    b.push_back(new X);
    for (int i = 0; i < b.size(); i++)
        cout << b[i]->vf() << endl;
    purge(b);
} ///:~
